I am building a bicycle on Simscape with imported CAD parts but keep getting the same error. Can someone help me please?

Hello,

I am now studying the behaviour of a bicyle and I am using Simscape to assemble the different parts of it (frame, handle, seat, wheels, etc...). However, I keep getting this error:

['Bicycle4']: The following errors were found in the model Bicycle4.

Caused by:

• ['Bicycle4']: Cycle detected in rigidity graph:
• World Frame 'Bicycle4/World Frame1' Rigid Transform 'Bicycle4/Rigid Transform' (B -> F)
• Solid 'Bicycle4/File Solid1' (R -> Frame1)
• Solid 'Bicycle4/File Solid' (Frame1 -> R)
• Rigid Transform 'Bicycle4/Rigid Transform1' (F -> B)
• World Frame 'Bicycle4/World Frame'

The connection from 'Bicycle4/File Solid1' port Frame1 to frame File_Solid_Frame1 is ignored for assembly. Break the cycle by explicitly removing this or a different block or connection to it. Resolve this issue in order to simulate the model.

Does anyone know what this error is and how I can fix it please?

Thank you very much.

Answer 1

[Rishi]

Hi Henintsoa,

I understand that you want to know why you're getting the error message 'Cycle detected ub rigidity graph'.

This is because SimMechanics does not allow creation of closed-loop system unless there are Joints present in the assembly. (such as a four-bar linkage).

If there are no Joint blocks in the assembly, you need not close the loop because it will not affect the behavious of the rigid body. For example, if you are creating a triangle using three bars 'A', 'B', and 'C', the connections 'A-B' and 'B-C' will suffice. Creating the connection 'C-A' as well will cause this error to be thrown.

Hope this helps!

[Henintsoa]

Hello Rishi,

Thank you very much for your answer. The explanation you gave was very clear and very helpful. I removed the link that closed my loop and did some re-arranging in my model and it is okay now. Thank you again.

Have a nice day/night.